1. Field of the Invention
The present invention generally relates to an optical reading apparatus having an optical scanner for scanning information on objects, and more particularly to an optical reading apparatus having a stationary-type optical scanner for scanning bar codes on articles of trade, which apparatus is used in a POS (Point of Sales) system provided in a store.
2. Description of the Related Art
Conventional optical reading apparatuses, such as bar code reading apparatus used in the POS system, are classified, based on setting forms of the optical scanners and directions in which scanning light beams travels from the optical scanner, into the following three types.
The first type is referred to as a horizontal setting form and beam upward emission type. This type of bar code reading apparatus is shown, for example, in FIG. 1. Referring to FIG. 1, a scanner unit 20 is horizontally set on the surface of a check-out counter 21. Scanning light 23 travels obliquely upward from a window 22 on the upper surface of the scanner unit 20. An operator takes out each article from an article basket 24 and moves it over the scanner unit 20 in a direction shown by an arrow 25. When an article is moved over the scanner unit 20, a bar code on the article is optically scanned by the scanning light 23 so as to be read. After the bar codes of all the articles have been read, the article basket 24 which is empty is moved over the scanner unit 20 as shown by an arrow 26.
The second type is referred to as a vertical setting form and beam frontward emission type. This type of bar code reading apparatus is shown, for example, in FIG. 2. Referring to FIG. 2, a scanner unit 30 stands on the check-out counter 21 so that a window 31 of the scanner unit 30 is vertical to the surface of the check-out counter 21. Scanning light 32 travels frontward (toward an operator) from the window 31. The operator takes out each article from the article basket 24 and moves each article, in a direction shown by an arrow 33, while positioning it in such a way that a bar code thereon faces the scanner unit 30. When each article passes through an area in front of the scanner unit 30, the bar code thereon is read. After the bar codes of all articles have been read, the article basket 24 which is empty is moved so as to slide on the check-out counter 21 as shown by an arrow 34.
The third type is referred to as an overhead setting form and beam downward emission type. This type of bar code reading apparatus is shown, for example, in FIG. 3. Referring to FIG. 3, a scanner unit 40 is supported by a post 41 as to be located above the check-out counter 21. A window from which scanning light 43 travels faces the surface of the check-out counter 21. That is, the scanning light 43 travels downward from the window 42 of the scanner unit 40. The operator takes out each article from the article basket 24 and moves each article, in a direction shown by an arrow 44, while positioning it in such a way that a bar code thereon is directed upward to face the scanner unit 40. After the bar codes of all the articles have been read, the article basket 24 which is empty is moved so as to slide on the check-out counter 21 as shown by an arrow 45.
In the first type of conventional bar code reading apparatus as shown in FIG. 1, there is no obstacle above the scanner unit 20, so that the operator can move articles more quickly than in the cases of the second and third types of conventional bar code reading apparatuses as shown in FIGS.2 and 3. In addition, since the scanning light 23 travels upward from the article basket 24, the scanning light 23 does not enter the article basket 24, thus preventing articles from being mistakenly read.
In the second and third types of conventional bar code reading apparatuses as shown in FIGS. 2 and 3, the article basket 24 can be moved so as to slide on the check-put counter 21 without hitting the article basket 24 on the scanner unit 30 or 40.
In the first and second types of conventional bar code reading apparatuses as shown in FIGS. 1 and 2, handling of a boat-shaped article as shown in FIG. 4 is inferior. A boat-shaped article 12 as shown in FIG. 4 is formed of a dish 10 in which food, such as raw fish or meat, is put and a wrapping sheet 11 by which the dish 10 is wrapped. A bar code label 13 on which a bar code is formed is attached to the wrapping sheet 11. When the boat-shaped article 12 is scanned by the first type of conventional bar code reading apparatus, the boat-shaped article 12 must be upside down so that the bar code label 13 faces the scanner unit 20. Thus, there is a case where the food in the dish 10 is deformed and/or food juice leaks out of the dish 10. When the boat-shaped article 12 is scanned by the second type of conventional bar code reading apparatus, the boat-shaped article 12 must be inclined so that the bar code label 13 faces the scanner unit 30. Thus, in this case, the same problem as in the case of the first type of conventional bar code reading apparatus occurs.
In addition, in the third type of conventional bar code reading apparatus, if the article basket 24 is mistakenly moved under the scanner unit 40, the scanning light 43 enters the article basket 24. In this case, bar codes or other articles in the article basket 24 are mistakenly read.